Drug Metabolism And Pharmacokinetics Research Articles

Abstract 3197: Addressing drug metabolism and pharmacokinetics (DMPK) challenges of small molecule-drug conjugates (SMDCs)

Abstract Background: SMDCs are gaining momentum with potential advantages over antibody-drug conjugates (ADCs), eg, better tumor penetration and lack of immunogenicity. We have developed a novel platform technology with tailored solutions for ADCs and SMDCs with intracellular and extracellular cleavage options. Key features of the SMDC technology comprise of a small molecule ligand such as an αvβ3 integrin binder showing efficient tumor homing and a linker extracellularly cleaved by neutrophil elastase (NE) in the tumor microenvironment allowing for seamless release of different payload classes.1 Our lead SMDC VIP2362 is currently in a Phase 1 clinical trial for the treatment of advanced solid tumors (NCT05712889). SMDCs often have a shorter half-life compared with ADCs, which may result in more frequent dosing schedules. Here we show significant reduction of clearance and drastic prolongation of half-life of SMDCs achieved by adding a second binding moiety. Methods: Payloads such as kinesin spindle protein inhibitors (KSPi), cyclin-dependent kinase 9 inhibitors (CDK9i), and monomethyl auristatin E (MMAE) have been linked via elastase-cleavable linkers to one or, via a branched linker, to two αvβ3 integrin binding moieties. Cytotoxicity of SMDCs was measured in cell lines with or without NE. Monovalent and bivalent SMDCs were investigated in DMPK studies in rats while monitoring the conjugate and the released payload. Results: Payloads were coupled to the NE-cleavable peptides via different linkages. MMAE was conjugated via sterically hindered ester bonds, CDK9i was conjugated via sulfoximide bonds, and KSPi payloads were coupled via amide bonds. Each of these SMDCs was highly stable in plasma and buffer. Without NE, in vitro cytotoxicity of SMDCs in each cell line was poor with IC50 in the micromolar range. In contrast, in the presence of NE, potency increased, and cytotoxicity (IC50) was in the low nanomolar to picomolar range depending on the cell line and payload. In each case, the SMDCs reached similar potency as the free payload indicating efficient cleavage of the SMDC by NE. In DMPK studies of SMDCs in rat, none or trace levels of free payload (<0.1% as compared to the respective conjugates) was measured. With each of the SMDCs and independent of the conjugated payloads, a remarkable impact on exposure was observed when attaching a second binding ligand. The SMDCs with two ligands showed a 37- to 81-fold reduced plasma clearance as compared with the respective monovalent SMDCs, which parallels a 12- to 57-fold increase in half-life (eg, 2.1 h and 28 h for mono and bivalent MMAE SMDCs respectively). Initial in vivo studies in a cell line-derived xenograft model showed efficacy of bivalent SMDCs with once weekly dosing. Conclusion: Our technology platform comprises NE-cleavable SMDCs with promising options to tune the DMPK profile for a longer half-life. 1. Lerchen et al, AACR (2023). 2. Lerchen et al, Cancers (2023). Citation Format: Anne-Sophie Rebstock, Hans-Georg Lerchen, Harvey Wong, Beatrix Stelte-Ludwig, Mareike Wiedmann, Amy J. Johnson, Raquel Izumi, Ahmed Hamdy. Addressing drug metabolism and pharmacokinetics (DMPK) challenges of small molecule-drug conjugates (SMDCs) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3197.

Abstract 5931: Investigating the therapeutic potential of STK17A inhibition in GBM

Abstract For decades, the survival rate for glioblastoma (GBM) has remained nearly stagnant, and currently the 5-year survival rate is only 5%. There is an unmet medical need for therapeutic development, as GBM is the most common primary brain tumor, yet only four FDA approved drugs have been developed for GBM over the last century. GBM is notoriously heterogeneous, and this has posed a challenge for researchers seeking to find therapeutic targets. However, by taking advantage of RNA sequencing, a potential biomarker and target for GBM has been identified: the kinase STK17A (Serine/Threonine Kinase 17A), also known as DRAK1. We confirmed that STK17A is overexpressed in brain cancers by analyzing public databases and single-cell RNA sequencing data from GBM patients, and further associated it with poor patient outcome. Little is known about STK17A, but it has been found to be involved with cell proliferation, tumorigenesis, and tumor metastasis. The role of STK17A in GBM pathophysiology and its therapeutic potential as a drug target remains a critical knowledge gap.In order to better understand STK17A’s role in GBM pathophysiology, we first knocked down STK17A in GBM cell lines and determined that STK17A had functional roles in proliferation and morphology. Similar conclusions were drawn after knocking down STK17A in vivo in GBM xenograft mouse models. These findings supported STK17A as a viable therapeutic target. We then designed and optimized novel brain-penetrant STK17A inhibitors with IC50 values of <20nM in enzyme assays and <1μM in cell-based targeting engagement and proliferative assays. The designed and prepared novel STK17A inhibitors were further evaluated through kinase enzymatic assays and biological assays as well as in vitro proliferation and toxicity assays. We further characterized the inhibitors by showing Drug Metabolism and Pharmacokinetics (DMPK) properties in vivo in mouse models at 10 mg/kg via oral administration. We then used these potent, selective, and highly brain penetrant STK17A inhibitors to investigate the anti-tumor effects of STK17A inhibition in GBM in vivo and demonstrate the efficacy of our novel STK17A inhibitors.In conclusion, this work seeks to contribute to the field of targeted therapies for GBM by optimizing and examining the first iterations of novel brain penetrant STK17A inhibitors, initiating studies for the treatment of GBM in vitro and in vivo, and providing proof of efficacy for further studies in GBM patients. Ultimately, the results from our findings will lead to novel strategies for targeted drug development and more robust therapeutic options for GBM patients. Citation Format: Jesus R. Castro. Investigating the therapeutic potential of STK17A inhibition in GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5931.

Cytotoxic and Antiproliferative Activity of LASSBio-2208 and the Attempts to Determine Its Drug Metabolism and Pharmacokinetics In Vitro Profile.

Inappropriate expression of histone deacetylase (HDAC-6) and deregulation of the phosphatidylinositol 3-kinase (PI3K) signalling pathway are common aberrations observed in cancers. LASSBio-2208, has been previously described as a dual inhibitor in the nanomolar range of HDAC-6 and PI3Kα and is three times more potent in inhibiting HDAC-6. In this paper we described the cytotoxic and antiproliferative potency of LASSBio-2208 on different tumour cell lines, its possible synergism effect in association with PI3K and HDAC-6 inhibitors, and its drug metabolism and pharmacokinetics (DMPK) in vitro profile. Our studies have demonstrated that LASSBio-2208 has moderate cytotoxic potency on breast cancer cell line MCF-7 (IC50 = 23 µM), human leukaemia cell line CCRF-CEM (IC50 = 8.54 µM) and T lymphoblast cell line MOLT-4 (IC50 = 7.15 µM), with no cytotoxic effect on human peripheral blood mononuclear cells (hPBMC). In addition, it has a good antiproliferative effect on MCF-7 cells (IC50 = 5.44 µM), low absorption by parallel artificial membrane permeability-gastrointestinal tract (PAMPA-GIT) and low permeation by parallel artificial membrane permeability-blood-brain barrier (BBB) (PAMPA-BBB), exhibiting high metabolic stability in rat plasma. Moreover, LASSBio-2208 exhibited synergism when combined with getadolisib and tubastatin A, using the concentrations corresponding to their CC50 values on MOLT-4 and CCRF-CEM cells.

Using Generative Modeling to Endow with Potency Initially Inert Compounds with Good Bioavailability and Low Toxicity.

In the early stages of drug development, large chemical libraries are typically screened to identify compounds of promising potency against the chosen targets. Often, however, the resulting hit compounds tend to have poor drug metabolism and pharmacokinetics (DMPK), with negative developability features that may be difficult to eliminate. Therefore, starting the drug discovery process with a "null library", compounds that have highly desirable DMPK properties but no potency against the chosen targets, could be advantageous. Here, we explore the opportunities offered by machine learning to realize this strategy in the case of the inhibition of α-synuclein aggregation, a process associated with Parkinson's disease. We apply MolDQN, a generative machine learning method, to build an inhibitory activity against α-synuclein aggregation into an initial inactive compound with good DMPK properties. Our results illustrate how generative modeling can be used to endow initially inert compounds with desirable developability properties.

The Comparison of Machine Learning and Mechanistic In Vitro-In Vivo Extrapolation Models for the Prediction of Human Intrinsic Clearance.

Accurate prediction of human pharmacokinetics (PK) remains one of the key objectives of drug metabolism and PK (DMPK) scientists in drug discovery projects. This is typically performed by using in vitro-in vivo extrapolation (IVIVE) based on mechanistic PK models. In recent years, machine learning (ML), with its ability to harness patterns from previous outcomes to predict future events, has gained increased popularity in application to absorption, distribution, metabolism, and excretion (ADME) sciences. This study compares the performance of various ML and mechanistic models for the prediction of human IV clearance for a large (645) set of diverse compounds with literature human IV PK data, as well as measured relevant in vitro end points. ML models were built using multiple approaches for the descriptors: (1) calculated physical properties and structural descriptors based on chemical structure alone (classical QSAR/QSPR); (2) in vitro measured inputs only with no structure-based descriptors (ML IVIVE); and (3) in silico ML IVIVE using in silico model predictions for the in vitro inputs. For the mechanistic models, well-stirred and parallel-tube liver models were considered with and without the use of empirical scaling factors and with and without renal clearance. The best ML model for the prediction of in vivo human intrinsic clearance (CLint) was an in vitro ML IVIVE model using only six in vitro inputs with an average absolute fold error (AAFE) of 2.5. The best mechanistic model used the parallel-tube liver model, with empirical scaling factors resulting in an AAFE of 2.8. The corresponding mechanistic model with full in silico inputs achieved an AAFE of 3.3. These relative performances of the models were confirmed with the prediction of 16 Pfizer drug candidates that were not part of the original data set. Results show that ML IVIVE models are comparable to or superior to their best mechanistic counterparts. We also show that ML IVIVE models can be used to derive insights into factors for the improvement of mechanistic PK prediction.

Novel inhibitors that target bacterial virulence identified via HTS against intra-macrophage survival of Shigella flexneri.

Shigella flexneri is a facultative intracellular pathogen that causes shigellosis, a human diarrheal disease characterized by the destruction of the colonic epithelium. Novel antimicrobial compounds to treat infections are urgently needed due to the proliferation of bacterial antibiotic resistance and lack of new effective antimicrobials in the market. Our approach to find compounds that block the Shigella virulence pathway has three potential advantages: (i) resistance development should be minimized due to the lack of growth selection pressure, (ii) no resistance due to environmental antibiotic exposure should be developed since the virulence pathways are not activated outside of host infection, and (iii) the normal intestinal microbiota, which do not have the targeted virulence pathways, should be unharmed. We chose to utilize two phenotypic assays, inhibition of Shigella survival in macrophages and Shigella growth inhibition (minimum inhibitory concentration), to interrogate the 1.7 M compound screening collection subset of the GlaxoSmithKline drug discovery chemical library. A number of secondary assays on the hit compounds resulting from the primary screens were conducted, which, in combination with chemical, structural, and physical property analyses, narrowed the final hit list to 44 promising compounds for further drug discovery efforts. IMPORTANCE The rapid development of antibiotic resistance is a critical problem that has the potential of returning the world to a "pre-antibiotic" type of environment, where millions of people will die from previously treatable infections. One relatively newer approach to minimize the selection pressures for the development of resistance is to target virulence pathways. This is anticipated to eliminate any resistance selection pressure in environmental exposure to virulence-targeted antibiotics and will have the added benefit of not affecting the non-virulent microbiome. This paper describes the development and application of a simple, reproducible, and sensitive assay to interrogate an extensive chemical library in high-throughput screening format for activity against the survival of Shigella flexneri 2457T-nl in THP-1 macrophages. The ability to screen very large numbers of compounds in a reasonable time frame (~1.7 M compounds in ~8 months) distinguishes this assay as a powerful tool in further exploring new compounds with intracellular effect on S. flexneri or other pathogens with similar pathways of pathogenesis. The assay utilizes a luciferase reporter which is extremely rapid, simple, relatively inexpensive, and sensitive and possesses a broad linear range. The assay also utilized THP-1 cells that resemble primary monocytes and macrophages in morphology and differentiation properties. THP-1 cells have advantages over human primary monocytes or macrophages because they are highly plastic and their homogeneous genetic background minimizes the degree of variability in the cell phenotype (1). The intracellular and virulence-targeted selectivity of our methodology, determined via secondary screening, is an enormous advantage. Our main interest focuses on hits that are targeting virulence, and the most promising compounds with adequate physicochemical and drug metabolism and pharmacokinetic (DMPK) properties will be progressed to a suitable in vivo shigellosis model to evaluate the therapeutic potential of this approach. Additionally, compounds that act via a host-directed mechanism could be a promising source for further research given that it would allow a whole new, specific, and controlled approach to the treatment of diseases caused by some pathogenic bacteria.

DruMAP: A Novel Drug Metabolism and Pharmacokinetics Analysis Platform.

We developed a novel drug metabolism and pharmacokinetics (DMPK) analysis platform named DruMAP. This platform consists of a database for DMPK parameters and programs that can predict many DMPK parameters based on the chemical structure of a compound. The DruMAP database includes curated DMPK parameters from public sources and in-house experimental data obtained under standardized conditions; it also stores predicted DMPK parameters produced by our prediction programs. Users can predict several DMPK parameters simultaneously for novel compounds not found in the database. Furthermore, the highly flexible search system enables users to search for compounds as they desire. The current version of DruMAP comprises more than 30,000 chemical compounds, about 40,000 activity values (collected from public databases and in-house data), and about 600,000 predicted values. Our platform provides a simple tool for searching and predicting DMPK parameters and is expected to contribute to the acceleration of new drug development. DruMAP can be freely accessed at: https://drumap.nibiohn.go.jp/.

Discovery of quinazolin-4-one-based non-covalent inhibitors targeting the severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2 Mpro)

The COVID-19 pandemic caused by SARS-CoV-2 continues to pose a great threat to public health while various vaccines are available worldwide. Main protease (Mpro) has been validated as an effective anti-COVID-19 drug target. Using medicinal chemistry and rational drug design strategies, we identified a quinazolin-4-one series of nonpeptidic, noncovalent SARS-CoV-2 Mpro inhibitors based on baicalein, 5,6,7-trihydroxy-2-phenyl-4H-chromen-4-one. In particular, compound C7 exhibits superior inhibitory activity against SARS-CoV-2 Mpro relative to baicalein (IC50 = 0.085 ± 0.006 and 0.966 ± 0.065 μM, respectively), as well as improved physicochemical and drug metabolism and pharmacokinetics (DMPK) properties. In addition, C7 inhibits viral replication in SARS-CoV-2-infected Vero E6 cells more effectively than baicalein (EC50 = 1.10 ± 0.12 and 5.15 ± 1.64 μM, respectively) with low cytotoxicity (CC50 ＞ 50 μM). An X-ray co-crystal structure reveals a non-covalent mechanism of action, and a noncanonical binding mode not observed by baicalein. These results suggest that C7 represents a promising lead for development of more effective SARS-CoV-2 Mpro inhibitors and anti-COVID-19 drugs.

METTL7A (TMT1A) and METTL7B (TMT1B) Are Responsible for Alkyl S-Thiol Methyl Transferase Activity in Liver.

S-methylation of drugs containing thiol-moieties often alters their activity and results in detoxification. Historically, scientists attributed methylation of exogenous aliphatic and phenolic thiols to a putative S-adenosyl-L-methionine (SAM)-dependent membrane-associated enzyme referred to as thiol methyltransferase (TMT). This putative TMT appeared to have a broad substrate specificity and methylated the thiol metabolite of spironolactone, mertansine, ziprasidone, captopril, and the active metabolites of the thienopyridine prodrugs, clopidogrel, and prasugrel. Despite TMT's role in the S-methylation of clinically relevant drugs, the enzyme(s) responsible for this activity remained unknown. We recently identified methyltransferase-like protein 7B (METTL7B) as an alkyl thiol methyltransferase. METTL7B is an endoplasmic reticulum-associated protein with similar biochemical properties and substrate specificity to the putative TMT. Yet, the historic TMT inhibitor 2,3-dichloro-α-methylbenzylamine (DCMB) did not inhibit METTL7B, indicating that multiple enzymes contribute to TMT activity. Here we report that methyltransferase-like protein 7A (METTL7A), an uncharacterized member of the METTL7 family, is also a SAM-dependent thiol methyltransferase. METTL7A exhibits similar biochemical properties to METTL7B and putative TMT, including inhibition by DCMB (IC50 = 1.17 μM). Applying quantitative proteomics to human liver microsomes and gene modulation experiments in HepG2 and HeLa cells, we determined that TMT activity correlates closely with METTL7A and METTL7B protein levels. Furthermore, purification of a novel His-GST-tagged recombinant protein and subsequent activity experiments prove that METTL7A can selectively methylate exogenous thiol-containing substrates, including 7α-thiospironolactone, dithiothreitol, 4-chlorothiophenol, and mertansine. We conclude that the METTL7 family encodes for two enzymes, METTL7A and METTL7B, which are now renamed thiol methyltransferase 1A (TMT1A) and thiol methyltransferase 1B (TMT1B), respectively, that are responsible for thiol methylation activity in human liver microsomes. SIGNIFICANCE STATEMENT: We identified methyltransferase-like protein 7A (thiol methyltransferase 1A) and methyltransferase-like protein 7B (thiol methyltransferase 1B) as the enzymes responsible for the microsomal alkyl thiol methyltransferase (TMT) activity. These are the first two enzymes directly associated with microsomal TMT activity. S-methylation of commonly prescribed thiol-containing drugs alters their pharmacological activity and/or toxicity, and identifying the enzymes responsible for this activity will improve our understanding of the drug metabolism and pharmacokinetic (DMPK) properties of alkyl- or phenolic thiol-containing therapeutics.

Design, synthesis, and pharmacological evaluation of N-(3-carbamoyl-1H-pyrazol-4-yl)-1,3-oxazole-4-carboxamide derivatives as interleukin-1 receptor-associated kinase 4 inhibitors with reduced potential for cytochrome P450 1A2 induction

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical molecule in Toll-like receptor/interleukin-1 receptor signaling and an attractive therapeutic target for a wide range of inflammatory and autoimmune diseases as well as cancers. In our search for novel IRAK4 inhibitors, we conducted structural modification of a thiazolecarboxamide derivative 1, a lead compound derived from high-throughput screening hits, to elucidate structure–activity relationship and improve drug metabolism and pharmacokinetic (DMPK) properties. First, conversion of the thiazole ring of 1 to an oxazole ring along with introduction of a methyl group at the 2-position of the pyridine ring aimed at reducing cytochrome P450 (CYP) inhibition were conducted to afford 16. Next, modification of the alkyl substituent at the 1-position of the pyrazole ring of 16 aimed at improving CYP1A2 induction properties revealed that branched alkyl and analogous substituents such as isobutyl (18) and (oxolan-3-yl)methyl (21), as well as six-membered saturated heterocyclic groups such as oxan-4-yl (2), piperidin-4-yl (24, 25), and dioxothian-4-y (26), are effective for reducing induction potential. Representative compound AS2444697 (2) exhibited potent IRAK4 inhibitory activity with an IC50 value of 20 nM and favorable DMPK properties such as low risk of drug–drug interactions mediated by CYPs as well as excellent metabolic stability and oral bioavailability.

Discovery of Novel Substrate-Competitive Lysine Methyltransferase G9a Inhibitors as Anticancer Agents.

Identification of structurally novel inhibitors of lysine methyltransferase G9a has been a subject of intense research in cancer epigenetics. Starting with the high-throughput screening (HTS) hit rac-10a obtained from the chemical library of the University of Tokyo Drug Discovery Initiative, the structure-activity relationship of the unique substrate-competitive inhibitors was established with the help of X-ray crystallography and fragment molecular orbital (FMO) calculations for the ligand-protein interaction. Further optimization of the in vitro characteristics and drug metabolism and pharmacokinetics (DMPK) properties led to the identification of 26j (RK-701), which is a structurally distinct potent inhibitor of G9a/GLP (IC50 = 27/53 nM). Compound 26j exhibited remarkable selectivity against other related methyltransferases, dose-dependent attenuation of cellular H3K9me2 levels, and tumor growth inhibition in MOLT-4 cells in vitro. Moreover, compound 26j showed inhibition of tumor initiation and growth in a carcinogen-induced hepatocellular carcinoma (HCC) in vivo mouse model without overt acute toxicity.

Drug Metabolism and Pharmacokinetics of Antisense Oligonucleotide Therapeutics: Typical Profiles, Evaluation Approaches, and Points to Consider Compared with Small Molecule Drugs.

Oligonucleotide therapeutics are attracting attention as a new treatment modality for a range of diseases that have been difficult to target using conventional approaches. Technical advances in chemical modification and drug delivery systems have led to the generation of compounds with excellent profiles as pharmaceuticals, and 16 oligonucleotide therapeutics have been marketed to date. There is a growing need to develop optimal and efficient approaches to evaluate drug metabolism and pharmacokinetics (DMPK) and drug-drug interactions (DDIs) of oligonucleotide therapeutics. The DMPK/DDI profiles of small molecule drugs are highly diverse depending on their structural and physicochemical characteristics, whereas oligonucleotide therapeutics share similar DMPK profiles within each chemistry type. Most importantly, the mechanisms and molecules involved in the distribution and metabolism of oligonucleotides differ from those of small molecules. In addition, there are considerations regarding experimental approaches in the evaluation of oligonucleotides, such as bioanalytical challenges, the use of radiolabeled tracers, materials for in vitro metabolism/DDI studies, and methods to study biodistribution. In this review, we attempt to summarize the DMPK characteristics of antisense oligonucleotide (ASO) therapeutics and discuss some of the issues regarding how to optimize the evaluation and prediction of the DMPK and DDI of ASOs.

Discovery of a Novel Potent and Selective HSD17B13 Inhibitor, BI-3231, a Well-Characterized Chemical Probe Available for Open Science.

Genome-wide association studies in patients revealed HSD17B13 as a potential new target for the treatment of nonalcoholic steatohepatitis (NASH) and other liver diseases. However, the physiological function and the disease-relevant substrate of HSD17B13 remain unknown. In addition, no suitable chemical probe for HSD17B13 has been published yet. Herein, we report the identification of the novel potent and selective HSD17B13 inhibitor BI-3231. Through high-throughput screening (HTS), using estradiol as substrate, compound 1 was identified and selected for subsequent optimization resulting in compound 45 (BI-3231). In addition to the characterization of compound 45 for its functional, physicochemical, and drug metabolism and pharmacokinetic (DMPK) properties, NAD+ dependency was investigated. To support Open Science, the chemical HSD17B13 probe BI-3231 will be available to the scientific community for free via the opnMe platform, and thus can help to elucidate the pharmacology of HSD17B13.

Advances in deep learning-based 3D molecular generative models

<p indent="0mm">Molecular generation, aiming at designing novel molecules with desired properties such as biological activity and drug metabolism and pharmacokinetic (DMPK) properties in a low-cost and high-efficient manner, is a fundamental problem in drug discovery. Recently, deep generative models have been widely used in drug discovery, along with numerous model architectures and optimization strategies being explored, most of which are developed to generate one-dimensional or two-dimensional molecular structures. Inspired by the rapid development of deep learning in processing geometric graph data, 3D generative models for molecular generation have also been proposed, gaining attention for their advantages and potential on direct 3D molecular conformation generation and structure-based drug discovery. This survey has offered a systematic summarization of existing research achievements of the domestic and foreign researchers in recent years in the aspects of 3D molecular generation. According to the input of 3D molecular generation algorithms, it is divided into latent variable-based generation, 2D graph-based generation and 3D geometry-based generation. Then, according to the output of 3D molecular generation algorithms, it is divided into goal-directed generation and non-goal-directed generation. Furthermore, the performance of different generative models on main public datasets is summarized, which proves the advantages and disadvantages of the various models. Finally, some promising research directions are proposed.

The discovery of (1R, 3R)-1-(3-chloro-5-fluorophenyl)-3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinoline-6-carbonitrile, a potent and selective agonist of human transient receptor potential cation channel subfamily m member 5 (TRPM5) and evaluation of as a potential gastrointestinal prokinetic agent

This publication details the discovery of a series of selective transient receptor potential cation channel subfamily M member 5 (TRPM5) agonists culminating with the identification of the lead compound (1R, 3R)-1-(3-chloro-5-fluorophenyl)-3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinoline-6-carbonitrile (39). We describe herein our biological rationale for agonism of the target, the examination of the then current literature tool molecules, and finally the process of our discovery starting with a high throughput screening hit through lead development. We also detail the selectivity of the lead compound 39 versus related family members TRPA1, TRPV1, TRPV4, TRPM4 and TRPM8, the drug metabolism and pharmacokinetics (DMPK) profile and in vivo efficacy in a mouse model of gastrointestinal motility.

Development of a three-step-based novel strategy integrating DMPK with network pharmacology and bioactivity evaluation for the discovery of Q-markers of traditional Chinese medicine prescriptions: Danlou tablet as an example

BackgroundQuality marker (Q-marker) serves an important role in promoting the standardization of the quality of traditional Chinese medicine (TCM) prescriptions. However, discovering comprehensive and representative Q-markers from TCM prescriptions composed of multiple components remains difficult. PurposeA three-step-based novel strategy integrating drug metabolism and pharmacokinetics (DMPK) with network pharmacology and bioactivity evaluation was proposed to discover the Q-markers and applied to a research example of Danlou tablet (DLT), a famous TCM prescription with remarkable and reliable clinical effects for coronary heart disease (CHD). MethodsFirstly, the metabolic profile in vivo of DLT was systemically characterized, and the pharmacokinetic (PK) properties of PK markers were then investigated. Secondly, an integrated network of “PK markers – CHD targets – pathways – therapeutic effects” was established to screen out the crucial PK markers of DLT against CHD. Thirdly, the crucial PK markers that could exhibit strong myocardial protection activity in the H9c2 cardiomyocyte model were selected as the candidate Q-markers of DLT. According to the proportion of their Cmax value in vivo, the candidate Q-markers were configured into a composition; the bioactivity was then evaluated to confirm their synergistic effect and justify their usage as Q-markers. ResultsFirst of all, a total of 110 DLT-related xenobiotics (35 prototypes and 75 metabolites) were detected in bio-samples, and the pharmacokinetic properties of 13 PK markers of DLT were successfully characterized, revealing the quality transitivity and traceability from prescription to in vivo. Then, 6 crucial PK markers with three topological features (degree, betweenness, and closeness) greater than the average values in the pharmacology network were screened out as the key components of DLT against CHD. Furthermore, among these 6 crucial PK markers, 5 components (puerarin, alisol A, daidzein, paeoniflorin, and tanshinone IIA) with strong myocardial protection activity were chosen as the candidate Q-markers to constitute a new composition. The composition activated the expression of the PI3K/AKT pathway and exhibited strong myocardial protection activity, and the effective concentrations (nM level) of these components in the composition were significantly lower than their individually effective concentrations (μM level), indicating that there was a certain synergistic effect between them. Hence, the 5 components with multiple properties, including testability, quality transitivity and traceability from prescription to in vivo, effectiveness, and compatibility contribution, were defined as comprehensive and representative Q-markers of DLT. ConclusionThis study not only presented a novel idea for the revelation of comprehensive and representative Q-markers in quality control research of TCM prescriptions, but also identified the reasonable Q-markers of DLT for the first time to improve the quality control level of DLT.

ADMET informatics of Tetradecanoic acid (Myristic Acid) from ethyl acetate fraction of Moringa oleifera leaves

In-silico Computer-Aided Drug Design (CADD) often comprehends virtual screening (VS) of datasets of natural pharmaco-active compounds for drug discovery protocols. Plant Based Natural Products (PBNPs) still, remains to be a prime source of pharmaco-active compounds due to their unique chemical structural scaffolds and functionalities with distinct chemical characteristic feature from natural source that are much acquiescent to drug metabolism and kinetics. In the Post-COVID-Era number of publications pertaining to PBNPs and publicly accessible plant based natural product databases (PBNPDBs) has significantly increased. Moreover, PBNPs are important sources of inspiration or starting points to develop novel therapeutic agents. However, a well-structured, in-depth ADME/Tox profile of PBNPs has been limited or lacking for many of such compounds, this hampers the successful exploitation of PBNPs by pharma industries. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties play key roles in the discovery/ development of drugs, pesticides, food additives, consumer products, and industrial chemicals. In the present study, ADMET-informatics of Tetradecanoic Acid (Myristic Acid) from ethyl acetate fraction of Moringa oleifera leaves to predict drug metabolism and pharmacokinetics (DMPK) outcomes has been taken up. This work contributes to the deeper understanding of Myristic acid as major source of drug from commonly available medicinal plant - Moringa oleifera with immense therapeutic potential. The data generated herein could be useful for NP based lead generation programs.&#x0D; Keywords: Moringa oleifera; Secondary Metabolites; Bioactive Substances; Myristic acid (MA); DMPK; ADME/Tox; Natural Products (NPs); PBNPs; PBNPDBs

Abstract 5461: H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC

Abstract BACKGROUND: Resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is a major challenge in non-small cell lung cancer (NSCLC) treatment. EGFR activating mutations, such as exon 19 deletions (Del19) and L858R substitution, have been reported in 10-50% of patients with NSCLC. Although these patients respond well to early generations of TKIs, acquired resistance by mechanisms such as T790M mutation compromises their efficacy. Recently, the C797S mutation in combination with Del19 or L858R, and with T790M, has emerged as one of the most common mechanisms underlying on-target resistance to a third generation EGFR TKI, osimertinib. We are developing a fourth-generation EGFR inhibitor, H002, with a wide spectrum and high selectivity to address the growing unmet needs in NSCLC patients harboring C797S mutation. METHODS: H002’s selectivity was assessed by KINOMEscan against more than 400 human kinases. A panel of 44 kinases was further evaluated to enable early identification of off-target effect. In vitro and in vivo anti-tumor efficacy was determined in drug-resistant mutant cell lines, CDX and PDX models. Single mutants (Del or L858R), double mutants (Del/T790M or L858R/T790M) and triple mutants (Del/T790M/C797S or L858R/T790M/C797S) as well as wild type EGFR were assessed. Drug metabolism and pharmacokinetic (DMPK) properties were further assessed. H002’s safety profile was evaluated in rats and beagle dogs, and by hERG potassium channel assay. Acute toxicity, and repeated dose GLP toxicity studies were also conducted in IND-enabling studies. RESULTS: High kinase selectivity and very low off-target effects were demonstrated by kinome-wide profiling and safety screening. H002 was highly active against all forementioned single, double or triple EGFR mutants (IC50 &amp;lt; 5 nM), and highly selective against wild type EGFR. H002 also exhibited potent anti-tumor effects in a dose-dependent manner in various CDX and PDX models. Excellent PK properties were observed in rats and beagle dogs with bioavailability over 70%. H002 was shown to cross the blood-brain barrier post i.g. administration in rats. No adverse effects of respiratory, cardiovascular and central nervous system were observed in safety studies. Repeated-dose toxicity studies only showed EGFR-related adverse reactions, such as gastrointestinal and liver toxicity, with high safety margin over 10-folds. CONCLUSION: H002 has been demonstrated as a promising next generation EGFR inhibitor, with high selectivity, a wide spectrum and potent anti-tumor activity against various EGFR activating mutations, favorable DMPK and safety profiles. It will be further developed as a fourth-generation EGFR inhibitor to overcome drug resistance in NSCLC. Citation Format: Wei Huang, Lin Zhu, Xiaoe Yan, Xin Huang, Jia Hao, Shan Li, Xiangyu Li, Zhiming Chen, Yunchuan Jia, Haibo Li, Jianming Zhang, Xianming Deng, Caihong Yun. H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5461.

Intestinal P‐glycoprotein (P‐gp) Contribution to Talinolol Pharmacokinetics in Human

ObjectiveUnderstanding the mechanisms of intestinal secretion and recirculation is important to the realm of drug metabolism and pharmacokinetics (DMPK). P‐glycoprotein (P‐gp), one of the major efflux transporters in the intestine, has broad substrate specificity and could contribute to the intestinal secretion/recirculation of drugs. The pharmacokinetic (PK) model incorporating intestinal P‐gp contribution will be able to accurately capture the interactions for the compounds of P‐gp substrate, allowing the model to aid in determining first in‐human (FIH) dose predictions as well as related potential drug‐drug interactions (DDIs). Talinolol, a beta‐adrenergic receptor antagonist utilized for cardioprotective and antihypertensive treatments, is a good substrate of P‐gp, and a double peak of plasma concentration has been observed. We hypothesize that intestinal secretion/recirculation by P‐gp could contribute to this unique plasma concentration‐time profile of talinolol. The aim of this study was to assess whether the double peak of plasma concentration of orally administered talinolol can be captured using physiological‐based pharmacokinetic (PBPK) modeling.MethodsThe plasma concentration‐time profiles of talinolol were obtained by digitizing literature data. The P‐gp‐mediated transport kinetics of talinolol were also obtained from Caco‐2 assays present in literature. Using the plasma concentration of talinolol data after intravenous (IV) administration, the intestinal secretion clearance (CLGI) was estimated using SimCYP (v19). After estimating CLGI, the regional absorption of talinolol affected by intestinal P‐gp was assessed using plasma talinolol concentration data after oral administration and the advanced dissolution, absorption, and metabolism (ADAM) model was subsequently generated utilizing SimCYP.ResultsCLGI of talinolol was estimated through using plasma concentration data of the drug after IV infusion reported by Schwarz et al., and CLGI was estimated to be 12.6 L/hr. This CLGI value was validated by capturing another plasma concentration‐time profile of talinolol after IV infusion reported by Westphal et al. The dual‐peak of the plasma talinolol concentration after oral administration was captured using ADAM model, but this model will be further refined to better capture this dual‐peak after oral administration of talinolol in human with consideration of regional differences of absorption and/or recirculation (i.e., more P‐gp in ileum compared to duodenum and jejunum).ConclusionA model was successfully generated to accurately capture the PK profiles of talinolol after IV administration. Further refinement of the model will be required for oral administration. The outcomes from the investigation essentially broaden our overall understanding of the processes underlying intestinal secretion and recirculation.

Linkers as Game-changers in PROTAC Technology: Emphasizing General Trends in PROTAC Pharmacokinetics for their Rational Design

Proteolysis Targeting Chimeras (PROTACs) are heterobifunctional molecules that act as degraders. They selectively remove disease-associated proteins by hijacking the Ubiquitin-Proteasome System (UPS). Chemically, they consist of three parts: an E3 ligase ligand, a target of interest (TOI) ligand, and a linker, which connects the two moieties. The rapid expansion of PROTAC Technology as an innovative therapeutic modality in cancer fostered the drug discovery effort to optimize their physicochemical properties. Due to their large size, their features are far from the traditional ‘drug-like’ properties. This short review highlights some of the structural modifications in the linker component to optimize the PROTAC Drug Metabolism and Pharmacokinetics (DMPK) profile. In particular, we discussed aspects related to solubility, cell permeability, active transporters efflux and, metabolic stability.